vfs: splice remove_suid() cleanup
generic_file_splice_write() duplicates remove_suid() just because it
doesn't hold i_mutex. But it grabs i_mutex inside splice_from_pipe()
anyway, so this is rather pointless.
Move locking to generic_file_splice_write() and call remove_suid() and
__splice_from_pipe() instead.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/splice.c b/fs/splice.c
index 633f58e..cece15b 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -811,24 +811,19 @@
{
struct address_space *mapping = out->f_mapping;
struct inode *inode = mapping->host;
- int killsuid, killpriv;
+ struct splice_desc sd = {
+ .total_len = len,
+ .flags = flags,
+ .pos = *ppos,
+ .u.file = out,
+ };
ssize_t ret;
- int err = 0;
- killpriv = security_inode_need_killpriv(out->f_path.dentry);
- killsuid = should_remove_suid(out->f_path.dentry);
- if (unlikely(killsuid || killpriv)) {
- mutex_lock(&inode->i_mutex);
- if (killpriv)
- err = security_inode_killpriv(out->f_path.dentry);
- if (!err && killsuid)
- err = __remove_suid(out->f_path.dentry, killsuid);
- mutex_unlock(&inode->i_mutex);
- if (err)
- return err;
- }
-
- ret = splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_file);
+ inode_double_lock(inode, pipe->inode);
+ ret = remove_suid(out->f_path.dentry);
+ if (likely(!ret))
+ ret = __splice_from_pipe(pipe, &sd, pipe_to_file);
+ inode_double_unlock(inode, pipe->inode);
if (ret > 0) {
unsigned long nr_pages;
@@ -840,6 +835,8 @@
* sync it.
*/
if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(inode))) {
+ int err;
+
mutex_lock(&inode->i_mutex);
err = generic_osync_inode(inode, mapping,
OSYNC_METADATA|OSYNC_DATA);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7e0fa9e..f413085 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1816,7 +1816,6 @@
extern void clear_inode(struct inode *);
extern void destroy_inode(struct inode *);
extern struct inode *new_inode(struct super_block *);
-extern int __remove_suid(struct dentry *, int);
extern int should_remove_suid(struct dentry *);
extern int remove_suid(struct dentry *);
diff --git a/mm/filemap.c b/mm/filemap.c
index 239d361..2dead9a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1655,7 +1655,7 @@
}
EXPORT_SYMBOL(should_remove_suid);
-int __remove_suid(struct dentry *dentry, int kill)
+static int __remove_suid(struct dentry *dentry, int kill)
{
struct iattr newattrs;